Image taken from Wikipedia
Flipping through the pages of my Chicago Manual of Style I found the answer to two questions that I’ve always had: You can start a sentence with “and” or “but”, and you can place a comma before “and”.
In case it is helpful for someone, this is what the Chicago Manual of Style says:
Beginning a sentence with a conjunction
There is a widespread belief—one with no historical or grammatical foundation—that it is an error to begin a sentence with a conjunction such as and, but, or so. In fact, a substantial percentage (often as many as 10 percent) of the sentences in first-rate writing begin with conjunctions. It has been so for centuries, and even the most conservative grammarians have followed this practice. Charles Allen Lloyd’s 1938 words fairly sum up the situation as it stands even today: “Next to the groundless notion that it is incorrect to end an English sentence with a preposition, perhaps the most wide-spread of the many false beliefs about the use of our language is the equally groundless notion that it is incorrect to begin one with ‘but’ or ‘and.’ As in the case of the superstition about the prepositional ending, no textbook supports it, but apparently about half of our teachers of English go out of their way to handicap their pupils by inculcating it. One cannot help wondering whether those who teach such a monstrous doctrine ever read any English themselves.”7 Still, but as an adversative conjunction can occasionally be unclear at the beginning of a sentence. Evaluate the contrasting force of the but in question and see whether the needed word is really and; if and can be substituted, then but is almost certainly the wrong word. Consider this example: He went to school this morning. But he left his lunchbox on the kitchen table. Between those sentences is an elliptical idea, since the two actions are in no way contradictory. What is implied is something like this: He went to school, intending to have lunch there, but he left his lunch behind. Because and would have made sense in the passage as originally stated, but is not the right word. To sum up, then, but is a perfectly proper way to open a sentence, but only if the idea it introduces truly contrasts with what precedes. For that matter, but is often an effective way of introducing a paragraph that develops an idea contrary to the one preceding it.
Serial commas: Items in a series are normally separated by commas. When a conjunction joins the last two elements in a series of three or more, a comma – known as the serial or series comma or the Oxford comma – should appear before the conjunction. Chicago strongly recommends this widely practiced usage, blessed by Fowler and other authorities, since it prevents ambiguity. If the last element consists of a pair joined by and, the pair should still be preceded by a serial comma and the first and.She took a photograph of her parents, the president, and the vice president.The owner, the agent, and the tenant were having an argument.I want no ifs, ands, or buts.Paul put the kettle on, Don fetched the teapot, and I made tea.The meal consisted of soup, salad, and macaroni and cheese.John was working, Jean was resting, and Alan was running errands and furnishing food.
Comma not needed. In a series whose elements are all joined by conjunctions, no commas are needed unless the elements are long and pauses helpful.
Is it by Snodgrass or Shapiro or Brooks?
You can turn left at the second fountain and right when you reach the temple, or turn left at the third
Brahms (Sonata No.3 D Minor)